Recently, image display apparatuses (e.g., a display apparatus, a television apparatus, and the like) that display an image using a display module, such as a liquid crystal panel, are rapidly becoming popular. Usually, the image display apparatus includes: a display panel part (image display apparatus main body) having a display module and a housing that houses therein the display module so that an image display face of the display module can be viewed from the outside; and a stand (pedestal part) supporting the display panel part and being capable of rotation, such as a swivel. If a liquid crystal panel is used in the display module, aback light is required. A linear light source, such as a cold cathode fluorescent lamp (CCFL) or an external electrode fluorescent lamp (EEFL), or an LED light source using an LED (light emitting diode) is used as the back light source, for example.
In such an image display apparatus, as the technique to connect the image display apparatus main body to the pedestal part that rotatably supports the housing, the following two configurations are known. Patent Document 1 (Japanese Patent Laid-Open No. 2008-003149) discloses a configuration, wherein a display apparatus is fixed in a self-standing manner via one metal plate which is installed on the upper part of a turntable of a pedestal part and is assembled by folding. Patent Document 2 (Japanese Utility Model Registration No. 3097842) discloses a configuration, wherein a column is fit into the center of a pedestal part, a swivel adjusting device is installed on the column and is connected to an image display apparatus main body, and the image display apparatus main body is adjusted at a predetermined angle.
Moreover, in such an image display apparatus, as the technique to fix the pedestal part that supports a housing, the following two configurations are known. Patent Document 3 (Japanese Utility Model Registration No. 3110945) discloses a configuration, wherein a front cabinet with a liquid crystal panel is fixed in a self-standing manner using a stand. Patent Document 4 (Japanese Patent Laid-Open No. 2005-352332) discloses a configuration, wherein a die-cast frame is spanned like a bridge between two sides (i.e., upper and lower sides or right and left sides) of the back face of a display module, and a bearing surface for attaching a stand is formed in the center or center bottom end of the frame.
Furthermore, in such an image display apparatus, as the technique to assemble and fix the housing for housing therein the display module, the following two configurations are known. Patent Document 5 (Japanese Patent Laid-Open No. 2008-298964) discloses a configuration, wherein a front cabinet is held by a front cover and a rear cabinet. Patent Document 6 (Japanese Patent Laid-Open No. 2000-305066) discloses a configuration that adapts to multiple types of color liquid crystal displays by modifying an internal bracket without providing a setscrew hole in a liquid crystal display base and its cover.
The conventional image display apparatus main body includes a frame-like bezel made of metal, wherein the frame-like bezel and a back plate (sheet-metal frame) of a display module are formed from an iron material, and wherein the liquid crystal module is relatively thick. For such an image display apparatus main body, recently, with an increase in the size of the screen, a reduction in the thickness and mass by reducing the thickness of an image display apparatus main body as much as possible is demanded. In order to achieve a reduction in the thickness and mass of the image display apparatus main body, a display module or the interior of a housing that occupies the most of the volume or mass of the interior of the image display apparatus main body needs to be thinned and the mass thereof needs to be reduced.
In the configuration disclosed in Patent Document 1, in the case of a large-size image display apparatus, since the display module is supported by the lower part of the image display apparatus, an appropriate size or mass is required for the bottom plate part (supporting base) of a pedestal part. Specifically, the width in the back and forth direction (in the thickness direction) of the image display apparatus increases and mass sufficient for preventing the image display apparatus from being easily overturned is required. In particular, if the pedestal part projects backward, a problem occurs that the image display apparatus main body cannot be moved to a wall for installation.
The configuration disclosed in Patent Document 2 causes a problem that because the stand is installed in the vicinity of the center of the bottom plate part of the rear cabinet, even if a reduction in the thickness of the display module is achieved, the thickness, volume, and mass of the image display apparatus main body increase by the thickness of the rear cabinet, and a reduction in the thickness and mass of the image display apparatus main body cannot be easily achieved.
The configuration disclosed in Patent Document 3 causes a problem that because the stand is installed at the center of the bottom plate part of the rear cabinet and a reinforcing plate is installed in the stand itself, even if a reduction in the thickness of the display module is achieved, the thickness, volume, and mass of the image display apparatus main body increase by the thickness of the rear cabinet or reinforcing plate, and a reduction in the thickness and mass of the image display apparatus main body cannot be easily achieved.
The configuration disclosed in Patent Document 4 causes a problem that because the stand is installed in the lower part of the frame that is spanned like a bridge, even if a reduction in the thickness of the display module is achieved, the thickness, volume, and mass of the image display apparatus main body increase by the thickness of the frame that is spanned like a bridge, and a reduction in the thickness and mass of the image display apparatus main body cannot be easily achieved.
Moreover, when a configuration that achieves a reduction in the thickness and mass of the display module or the image display apparatus main body is employed, the mass of a frame member or the like that supports the display module is reduced and therefore the strength or rigidity of the whole image display apparatus may decrease as compared with the conventional configuration.
When each of the configurations disclosed in Patent Documents 1 to 4 is applied to a configuration that achieves a reduction in the thickness and mass of the display module or image display apparatus main body, a stand is installed in a part of the frame (sheet-metal frame) of a back light (e.g., in the lower part of the frame of the back light). For this reason, the load on the frame of the back light may concentrate on a part of the frame when the image display apparatus main body is tilted forward and installed or depending on the use conditions, such as the ambient temperature or the like. As a result, the strength or rigidity of the display module or the whole image display apparatus cannot be maintained, and a bend, distortion, or the like may occur in a part of the back light and may degrade the display image quality, such as a degradation in the uniformity of luminance of a screen.
Furthermore, there is also a problem that heat is unlikely to be radiated from the inside of the housing to the outside because the thickness of the image display apparatus main body is reduced. In particular, since the housing is covered with a resin material having a poor thermal conductivity, there is a problem that the heat generated from a driver part and back light part of a liquid crystal panel or the heat generated from a power supply part, and signal processing part, and the like of an image display apparatus is likely to be accumulated inside the housing.
In addition, with the increase of the popularity of the image display apparatus, market demands for the aesthetic appearance in appearance design, such as a reduction in the width of a frame edge, for example, which reduces the width of an outer frame (frame edge portion) surrounding the display face of a display panel part as narrow (thin) as possible, are becoming strong, and an image display apparatus achieving such a reduction is always expected to be provided. Moreover, the interior nature of a home electric appliance is also emphasized. In portions, such as right in front, right beside, right behind, or the like, which are likely to catch the eyes of a user, a design is also requested, wherein the exterior face is designed so as to be flat as much as possible by eliminating or hiding the fastening portions of screws and also by hiding the end faces of members.
Usually, the image display apparatus main body includes a housing being made of resin (plastic) and comprising a combination of a front cover on the front face side (hereinafter, referred to as an F cover) and a rear cover on the back face side (hereinafter, referred to as an R cover). The resin-made housing is a molding member by injection molding. Note that in the market, there are also some image display apparatuses with a housing comprising a metal member. However, for example, if this metal housing is applied to a large-size screen with the size equal to or greater than 30 inches, there is a problem that the mass of the whole image display apparatus increases.
If a resin-made housing is applied to each of the configurations disclosed in Patent Documents 5, 6, the resin-made housing is suitable in a relatively small-size image display apparatus while in a relatively large-size image display apparatus, there is a problem in that the manufacturing variation of the resin-made housing cannot be neglected. The resin-made molding member causes a thermal shrinkage when it is cooled after injection molding, and its shape changes in the direction of slightly shrinking. Since this thermal shrinkage occurs locally, the resin-made housing is designed taking into consideration the variation in the shrinkage amount in advance at the time of design. However, in a large-size image display apparatus, since the shrinkage amount increases, the variation occurs between the shrinkage amount of the F cover and the shrinkage amount of the R cover. For this reason, at the time of assembly of the F cover and the R cover, the probability of occurrence of a defective product having an unallowable variation in the shrinkage amount increases, resulting in an increase in the cost of the image display apparatus.
As a method of suppressing the variation in the shrinkage amount due to thermal shrinkage, a method of increasing the number of fastening portions of screws when assembling the F cover and the R cover can be contemplated. However, if the number of fastening portions of screws is increased, there are problems that the number of components or the assembly man-hours increases and that the aesthetic appearance in appearance design degrades.